Large-scale weak lensing convergence in nonlinear general relativity

Fuente: arXiv
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Main Author: Macpherson, Hayley J.
Format: Preprint
Published: 2026
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author Macpherson, Hayley J.
author_facet Macpherson, Hayley J.
contents In this work we investigate the weak lensing convergence using an end-to-end nonlinear general relativistic framework. Combining numerical relativity simulations of large-scale structure formation with general relativistic ray-tracing, we compare our nonlinear calculation to the expectation based on perturbation theory for a set of 20 synthetic observers. We focus on large angular scales $\ell < 100$ across a broad range of redshifts with $0.05<z<3$. We confirm the importance of Doppler lensing for redshifts below $z\sim$0.6, as predicted by previous works. On average across our observers, linear perturbation theory predicts the nonlinear convergence to within 3-30% across all redshifts and angular scales we study. In general, we find smaller angular scales are better matched by linear theory than larger angular scales. While we cannot definitively identify the source of the discrepancy, for our particular study of redshift slices on observers' light cones the differences are mostly below the level of cosmic variance.
format Preprint
id arxiv_https___arxiv_org_abs_2603_24838
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Large-scale weak lensing convergence in nonlinear general relativity
Macpherson, Hayley J.
Cosmology and Nongalactic Astrophysics
General Relativity and Quantum Cosmology
In this work we investigate the weak lensing convergence using an end-to-end nonlinear general relativistic framework. Combining numerical relativity simulations of large-scale structure formation with general relativistic ray-tracing, we compare our nonlinear calculation to the expectation based on perturbation theory for a set of 20 synthetic observers. We focus on large angular scales $\ell < 100$ across a broad range of redshifts with $0.05<z<3$. We confirm the importance of Doppler lensing for redshifts below $z\sim$0.6, as predicted by previous works. On average across our observers, linear perturbation theory predicts the nonlinear convergence to within 3-30% across all redshifts and angular scales we study. In general, we find smaller angular scales are better matched by linear theory than larger angular scales. While we cannot definitively identify the source of the discrepancy, for our particular study of redshift slices on observers' light cones the differences are mostly below the level of cosmic variance.
title Large-scale weak lensing convergence in nonlinear general relativity
topic Cosmology and Nongalactic Astrophysics
General Relativity and Quantum Cosmology
url https://arxiv.org/abs/2603.24838